I have a terrible time remembering the content, or "flow" of my speeches. I'm prone to blanking on what's supposed to come next. I've tried several techniques with varying success, and want to share one of the ones that has worked best for me -- mindmapping.
To use mindmapping, I start from a central idea (my topic), and then I place my content, in order, around that center. When I need to recall specifics about a subtopic, I likewise arrange subitems around that subtopic. I prefer drawings and pictures to words because it's easier for me to remember the pictures as I move through my speech. It's also very easy to glance at the diagram as "notes" to figure out what comes next, without having to try to read a lot of notes to find my place. I use the drawing both for rehearsal (to memorize the order of my content), and sometimes for the performance as well (as notes).

I've shown the mindmap I used for one of my actual speeches. (Click on the diagram for a larger version.) The center was left blank in this case because I had no trouble remembering the topic -- it was "Joined at the Hip". The speech begins in the upper left (about 11 o'clock), and progresses clockwise around the center circle. If you want to hear the corresponding speech, it will be available here for a limited time.
This technique works extremely well for me because I am a visually-oriented person. I can easily visualize this diagram in my head after seeing it a few times. Having everything as drawings helps especially in this regard -- words in the same locations would be much harder to picture in my head.
Remembering the progression through your content can be challenging, and I recommend using whatever works best for you. Mindmapping has worked well for me, and can be a powerful technique to improve your recall of your speeches. Try it the next time if you find yourself during a speech wondering, "What do I say next?"